ASoC: SOF: hda-stream: only enable DPIB if needed

The existing code is inconsistent, we should only enable DPIB if the
'use_posbuf' field is true.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Péter Ujfalusi <peter.ujfalusi@linux.intel.com>
Link: https://lore.kernel.org/r/20211207193947.71080-5-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/intel/hda-stream.c

@@ -626,9 +626,10 @@ int hda_dsp_stream_hw_params(struct snd_sof_dev *sdev,
 			  sd_offset + SOF_HDA_ADSP_REG_CL_SD_BDLPU,
 			  upper_32_bits(hstream->bdl.addr));
 
-	/* enable position buffer */
-	if (!(snd_sof_dsp_read(sdev, HDA_DSP_HDA_BAR, SOF_HDA_ADSP_DPLBASE)
-				& SOF_HDA_ADSP_DPLBASE_ENABLE)) {
+	/* enable position buffer, if needed */
+	if (bus->use_posbuf && bus->posbuf.addr &&
+	    !(snd_sof_dsp_read(sdev, HDA_DSP_HDA_BAR, SOF_HDA_ADSP_DPLBASE)
+	      & SOF_HDA_ADSP_DPLBASE_ENABLE)) {
 		snd_sof_dsp_write(sdev, HDA_DSP_HDA_BAR, SOF_HDA_ADSP_DPUBASE,
 				  upper_32_bits(bus->posbuf.addr));
 		snd_sof_dsp_write(sdev, HDA_DSP_HDA_BAR, SOF_HDA_ADSP_DPLBASE,